Pitchometer support



y 1951 w. s. MGKINSTRY ET AL 2,550,707

PITCHOMETER SUPPORT Filed Sept. 17, 1945 frg i l3 '0 lo I9 23 2| 22 l8 l7 l4 l5 r I 5 17 I8 1 o M l3 '6 O INVENTORS m lo ,3 H WILLIAM E. LITTLE 3 MLLIAM E7. MEKINE TRY ATTORNEY Patented May 1, 1951 PITCHOMETER SUPPORT William S. McKinstry and William E. Little,

. Richmond, Calif.

Application September 17, 1945, Serial No. 616,952

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 3 Claims.

This invention relates to a support for pitchonieters or the like and more particularly to a support adapted to secure such devices to propeller hubs.

In the manufacture of propellers for use on ships it is customary practice to form the propeller as a rough casting and then to lay out and machine the finished propeller from the casting.

' A measuring device known as a pitchometer is commonly employed to determine the thickness of material to be removed from the casting at each point on the blades in order to provide the desired pitch. The pitchometer i secured to the hub of the casting and the determination requires measurements of a high degree of precision.

Supports heretofore used for securing a pitchometer to a propeller hub have been designed to be secured only to a finished hub; consequently, it has beennecessary to lay out and machine the hub before a pitchoineter could be employed to lay out the blades. This practice has necessitated an extra machining operation and furthermore, after the hub has been machined, it is not pos sible to change the center axis of a propeller to balance the material to be :removedfrom each blade;

The principal objects of the present invention are to provide a support for pitchorneters or the like adapted to be secured to an unmachined hub of a propeller casting and to provide a support of the type referred to that enables the center axs of the propeller to be shifted to balance the material to be removed from the different blades.

It is a further object of the invention to provide for carrying out the foregoing objects in a facile, i

economical and efficient manner.

In accomplishing these and other objects of the present invention, we have provided improved A pitchozneter, designated generally as 2, is

mounted on the propeller casting l and is'used to determine the thickness of material to be removed from the blades to finish the propeller. The pitchometer 2 is secured to the propeller casting I by asupport designated generally as 3.

in the accompanying drawing,

The propeller casting l comprises ahub 4 and a plurality of blades 5, in this case five in number. Before the propeller casting may be finished it is necessary to determine the thickness of the material to be machined from each blade at each point thereon and the pitchometer 2 is employed for this purpose.

The pitchometer 2 comprises a shaft 6, an arm l and a. gauge rod 8. The arm I is pivotaliy mounted on the shaft 6 and the gauge rod 8 is adjustably mounted on the arm 7. The construction ofthe pitchometer is not a part of this invention; hence, it i not described in further detail.

The support 3 of our invention comprises a base plate 9 preferably substantially circular in outline and having substantially planar faces on opposite sides thereof.

A plurality of inverted L-shaped clamp brackets it are secured to the under face of the base plate 9 as by the bolts l I. Preferably the lateral legsOf' the brackets l8 are slotted to receive the bolts l I to permit radialadjustment of the brackets with respect to the plate 9. The brackets II! have tapped bores in their depending legs and a stud i2 is 'tlireadedly engaged in each of the tapped bores. The studs IZ are adapted to engage the peripheral wall of the hub of a ing to secure the'support thereto.

A plurality of legs 53 are threadedly engaged in suitable tapped bores in the base plate 9 for vertical adjustment thereon. Preferably one leg I3 is provided adjacent each bracket H]. The lower ends of the legs l3 are adapted to re t against the upper surface of the propeller casting hub 4.

A center plate It is supported on the upper surface of the base plate 9. The latter has a pair of diametricall opposed radial grooves l5 inits upper face and the centerplate M has projecting guide portions i3 adapted to ride within the grooves I5, Fig. 2. The center plate E4 i 'thus supported on the base plate 9 in such manner that it may be adjusted thereacross in a substantially straight line in radial directions.

The base plate 9 has a pair of upstanding bosses I! on its upper face that have tapped bores therethrough substantially radially aligned with the grooves 15. A stud i8 is threadedly engaged in the bore of each boss I! and the inner ends thereof are adapted to engage the peripheral face of the center plate It to secure the center plate in adjusted position with respect to the base plate 9.

A block is is supported on the upper face of the center plate id. The upper face of the latter has a pair of diametrically opposed radial grooves 26 extending substantially perpendicularly to the propeller castprojecting guide portions 16 and grooves IS. The block [9 has downwardly projecting guide portions engaged within the grooves 20.

A pair of upstanding bosses 2| are provided on the upper face of the center plate [4 and have tapped bores therethrough substantially radially alignedwith the-grooves 20. A stud 22 is threadedly engaged in the bore of each boss 2| to secure the block 19 in adjusted position on the center plate 4.

The upper face of the block l9 has an"aper ture 23 adapted to receive and support the'base of the pitchometer shaft 6.

Operation.

The support is secured to the hub of a rough casting of a propeller. The studs 12 are rotated into clamping engagement with the :peripheral face of the hub. The legs l3 are rotated into engagement with the upper face of the hub and the support leveled with respect to the propeller Ceyadjustment of the legs. is adjusted acrossthe base plate-9 and'the block The center plate 1 4 l 9 is adjusted across the centerplate- I4 until the center axis of the p-itchometer shaft 6 is approxi- -mately aligned with the center axis of the hub 4.

Measurements are taken with the pitchometer to determine approximately the amount of material that must be removed from each blade.

-;Ordinarily it will .be found that aconsiderably .greateramountof material must be removed from .some blades than others. Thepositionof the :p-itchometer shaft with respect to the hub is then adjusted laterally to balance as-nearly as "possible the-amount-of material to be removedfrom leach blade.

thereon or therefor.

We claim: 1.,A pitchometer support comprising a base plate havingsubstantially planar faces on opposite sides thereof, aplurality .of clamp brackets secured to one of said faces, means on said brackets for engaging a propeller.hub, a plurality of legs secured to saidplate and being perpendicularly disposed to .a planar face thereof and adjustable as .to effective length, a center ill plate having substantially planar faces on opposite. sides thereof supported on the opposite face of said base plate for adjustment in the plane of saidopposite face in a substantially straight line, means securing said center plate in adjusted position-on said base plate, a block adapted to receive a p-itchomete'r shaft supported on said center plate for adjustment in the plane of the face iof said center plate in a substantially straight line substantially perpendicular to said first named "straight line, and means securing said blockin adjusted position with respect to said "center plate.

2. A pitchometer support comprising a base plate,- a plurality of clamp brackets secured to said base plate, a plurality of legs secured to said base plate and being adjustable as to effective length, a center plate supported on said base plate'for adjustment thereon in a substantially straight line, means securing said center plate in adjusted position on said base plate, a block adapted to receive a pitchometer shaft supported on said center plate for adjustment in a substantially straight line substantially perpendicular to said first named straight line, and means securing said block in adjusted position with re- 'spectto said center plate.

3. A support comprising a base plate, vertically adjustable means for leveling said plate on a 'hub,laterally adjustable means for securing said plate to said hub for lateral adjustment thereon, means supported on said base plate for receivinganobject to be carried thereby, means laterally adjustable in two substantially mutually perpendicular directions for laterally adjustingsaid object-receiving means on said base .plata'ahd means securing said supported means in adjusted position.

WILLIAM S. MCKINSTRY. WILLIAM E. LITTLE.

REFERENCES CITED Thejfollowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 507,047 Strickland Oct. 17, 1893 720,844 Rafferty Feb. 17, 1903 918,190 Van Nagy Apr. 13, 1909 21,736,247 'Bodenlos Nov. 19, 1929 2,132,170 Langsner Oct. 4, 1938 --2,1=32,407 Fowler Oct. 11, 1938 2,172,368 Eby Sept. 12, 1939 2,414,777 Thomas Jan. 21, 1947 FOREIGN PATENTS .Number Country Date 632,261"; France Oct. 1, 1927 

